1. Field of the Invention
The present invention relates to a paper shredder, and more particularly to blades of a paper shredder. The paper shredder has two rotary cutters each with multiple blades. Each blade has a first cutting blade with multiple first cutting edges and a second cutting blade with multiple cutting edges. Both the first and the second cutting blades are distributed in a non-equiangular manner and each of the first cutting edges is offset to each one of the second cutting edges, so that there is only one cutting edge engages with the paper to be shredded.
2. Related Prior Art
A conventional paper shredder, when operated, will automatically have the shredded paper fallen into the trash can. However, having the shredded paper fallen into the trash can, the motor of the paper shredder needs to rotate in a reversed direction so as to allow the shredded paper to escape from the rotary cutters to smoothly fall into the trash can, which allows a small amount of shredded paper stuck in the shredder. When the amount of shredded paper increases, the paper shredder will not function normally because multiple cutting edges simultaneously engage with the paper to be shredded. Thus a user will have to disassemble the paper shredder to clean the shredded paper stuck in the shredder to resume the function of the paper shredder. To have a better understanding of the function of the rotary cutters of a paper shredder, a pair of conventional rotary cutters are shown in FIG. 1. The conventional paper shredder has two rotary cutters (1,1xe2x80x2) each securely mounted on a polygonal axle (2) (a hexagonal axle is shown in the drawing) and each oppositely rotated with respect to each other. Each rotary cutters (1,1xe2x80x2) has multiple cutting blades (4) each spaced apart with one another by a spacer (6) so as to have the multiple blades (4) alternately mounted to each other. Each cutting blade (4) has a through hole (not numbered) defined to correspond to the axle (2) and multiple cutting edges (8) formed on the cutting blade (4) in a equiangular manner. The conventional rotary cutters do have the required performance, however, they still suffer several drawbacks.
1. The cutting edges (8) are equally distributed on the cutting blade (4) so that the cutting force can not evenly distributed along the axial direction of the axle. That is, at least two cutting edges (8) are in contact with the paper to be shredded. In order to provide each of the cutting edges (8) the sufficient power to accomplish the required performance, the paper shredder shall need a motor with a large power, which consumes a large amount of energy.
2. Because there are more than two cutting edges (8) are in contact with the paper, so that the conventional paper shredder create large noise.
3. The gear assembly in the transmission assembly will have to bear a large amount of load due to the engagement of more than two cutting edges with the paper, which results in that the gear assembly will be easily broken.
4. A large amount of paper are being shredded by more than two cutting edges so that the advancement of the paper is not smooth.
The present invention provides an improved blade of a paper shredder to overcome the above mentioned shortcomings.
The primary objective of the invention is to provide an improved blade for a paper shredder to evenly distributed the shredding force to each of the cutting edges so as to lessen the load on the transmission device of the paper shredder.
Another objective of the invention is to provide an improved blade for a paper shredder. The blade has a first cutting blade and a second cutting blade. Each of the first and the second cutting blades has alternately positioned cutting edges, such that when shredding the paper, only one cutting edge engages with the paper to be shredded. With such an arrangement, the noise of shredding the paper is greatly reduced.